Position signals from satellite navigation systems are used in a wide range of applications to determine a position. The most widely used satellite navigation system is GPS (global positioning system), which has been established by the USA. Other satellite navigation systems include GLONASS, a satellite navigation system provided by Russia, Galileo, the satellite navigation system currently being built by the European Union and the European Space Agency, or Compass, a navigation system under development by China.
In particular, such position systems are increasingly used by mobile electronic devices like mobile phones or digital cameras to determine the position of the device.
However, positioning systems based on satellite navigation position signals may only provide limited service availability in urban and indoor environments due to attenuation, shadowing and multipath fading effects in urban canyons and indoor areas. This is at least partially due to the frequency range used by such systems which is rather effectively attenuated by walls, buildings and the like.
A general alternative to satellite-based navigation and position determination is land-based navigation and position determination. For example, before the implementation of GPS, marine positioning receivers in ships were often based upon LORAN (long range navigation). LORAN is a world wide terrestrial navigation system using low frequency radio transmissions. Somewhat similar to GPS, it uses multiple transmitters to determine the location and speed of a user via trilateration. The most common LORAN variant is LORAN-C which transmits short pulses at a frequency of approximately 100 kHz in certain intervals. LORAN-C transmitter stations are usually ground-based and equipped with antennas about 411 m high which have transmit powers up to 4 MW. Many nations are users of the system, including European nations, the USA, Canada, Japan, China, India and several Middle Eastern countries. Russia uses a nearly identical system in the same frequency range, called CHAYKA, which is compatible to LORAN-C as it also transmits short 100 kHz pulses.
Various enhancements like E-LORAN (enhanced LORAN) allow for an accuracy of up to 8 m, which makes it a possible substitute for GPS in environments where receiving GPS or other satellite navigation position signals is difficult.
However, additionally integrating a separate receiver for such LORAN signals in mobile electronic devices or other devices may be undesirable as additional components, chip areas, antennas and the like may be needed.